1. Field of the Invention
The present invention relates to a process cartridge and an image forming apparatus on which such a process cartridge can be mounted. Such an image forming system may be embodied, for example, as an electrophotographic copying machine, a laser beam printer, a facsimile, a word processor, or the like.
2. Related Background Art
In image forming systems such as copying machines, a latent image is formed by selectively exposing an uniformly charged, image bearing member, the latent image is then visualized with toner, and then the toner image is transferred onto a recording sheet, thereby forming an image on the recording sheet. In such image forming systems, whenever the toner is used up, it must be replenished with new toner. The toner replenishing operation not only is troublesome, but also often causes contamination of the surroundings. Further, since the maintenance of various elements or members can be performed only by an expert in the art, most of the users are inconvenienced.
In order to eliminate such drawback and inconvenience, an image forming system, wherein parts such as a developing device which toner therein is used up or an image bearing member which a service life thereof has expired, can easily be exchanged, thereby facilitating the maintenance, by assembling the image bearing member, a charger, the developing device and a cleaning device integrally as a process cartridge which can be removably mounted within the image forming system has been proposed and put into practical use, for example, as disclosed in U.S. Pat. Nos. 3,985,436, 4,500,195, 4,540,268 and 4,627,701.
In the conventional process cartridges, there was provided a gripper used when a process cartridge was mounted within or dismounted from an image forming system. On the other hand, an opening of a toner containing portion for containing toner used in a developing operation was sealingly closed by a seal, and a pull aiding member for removing the seal from the opening was provided to protrude from a frame of the process cartridge. The gripper and the pull aiding member were independently arranged with respect to the frame.
However, in the above-mentioned conventional process cartridges, since the simple construction wherein the pull aiding member is merely protruded from the frame was adopted, there arose a problem that it was difficult for an operator to know the fact that he forgot to remove the seal.
Furthermore, since it was feared that the pull aiding member was damaged when a new process cartridge was unpacked, the pull aiding member must be stronger, thus increasing manufacturing costs.